RE: [PATCH net-next] selftests/xsk: decouple xskxceiver and xdp apps from test_progs objects

-----Original Message-----
From: Andrii Nakryiko <redacted>
Sent: Tuesday, July 28, 2026 4:05 AM
To: Vyavahare, Tushar <redacted>
Cc: netdev@vger.kernel.org; Karlsson, Magnus
[off-list ref]; Fijalkowski, Maciej
[off-list ref]; stfomichev@gmail.com;
kernelxing@tencent.com; davem@davemloft.net; kuba@kernel.org;
pabeni@redhat.com; ast@kernel.org; daniel@iogearbox.net; Sarkar,
Tirthendu [off-list ref]; bpf@vger.kernel.org
Subject: Re: [PATCH net-next] selftests/xsk: decouple xskxceiver and xdp apps
from test_progs objects

On Sat, Jul 18, 2026 at 6:46 AM Tushar Vyavahare
[off-list ref] wrote:

quoted

Build xskxceiver, xdp_hw_metadata, and xdp_features from explicit
source lists instead of reusing helper objects produced by test_progs rules.

Reusing shared objects such as network_helpers.o and xsk.o can pull in
test_progs-only dependency chains and trigger unrelated libarena
builds when invoking a single target.

Keep these standalone binaries self-contained so each target builds
only its own required sources and BPF skeleton dependencies.

Signed-off-by: Tushar Vyavahare <redacted>
---
 tools/testing/selftests/bpf/Makefile | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile

b/tools/testing/selftests/bpf/Makefile
index b642ee489ea6..a6f0ed10ccb4 100644

--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile

@@ -934,17 +934,27 @@ $(OUTPUT)/test_verifier: test_verifier.c

verifier/tests.h $(BPFOBJ) | $(OUTPUT)

quoted

        $(call msg,BINARY,,$@)
        $(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@

-# Include find_bit.c to compile xskxceiver.
-EXTRA_SRC := $(TOOLSDIR)/lib/find_bit.c prog_tests/test_xsk.c
prog_tests/test_xsk.h
-$(OUTPUT)/xskxceiver: $(EXTRA_SRC) xskxceiver.c xskxceiver.h
$(OUTPUT)/network_helpers.o $(OUTPUT)/xsk.o
$(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ) | $(OUTPUT)
+# Keep xskxceiver independent from test_progs object dependencies.
+XSKXCEIVER_SRC := xskxceiver.c xsk.c network_helpers.c \
+                 $(TOOLSDIR)/lib/find_bit.c prog_tests/test_xsk.c
+$(OUTPUT)/xskxceiver: $(XSKXCEIVER_SRC) xskxceiver.h xsk.h

network_helpers.h \

quoted

+                          prog_tests/test_xsk.h test_progs.h bpf_util.h \
+                          $(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ) |
+$(OUTPUT)
        $(call msg,BINARY,,$@)
        $(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@

-$(OUTPUT)/xdp_hw_metadata: xdp_hw_metadata.c
$(OUTPUT)/network_helpers.o $(OUTPUT)/xsk.o
$(OUTPUT)/xdp_hw_metadata.skel.h | $(OUTPUT)
+XDP_HW_METADATA_SRC := xdp_hw_metadata.c xsk.c network_helpers.c

\

quoted

+                              $(TOOLSDIR)/lib/find_bit.c
+$(OUTPUT)/xdp_hw_metadata: $(XDP_HW_METADATA_SRC)

xdp_metadata.h \

quoted

+                          xsk.h network_helpers.h test_progs.h bpf_util.h \
+                          $(OUTPUT)/xdp_hw_metadata.skel.h $(BPFOBJ)
+| $(OUTPUT)
        $(call msg,BINARY,,$@)
        $(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@

-$(OUTPUT)/xdp_features: xdp_features.c $(OUTPUT)/network_helpers.o
$(OUTPUT)/xdp_features.skel.h | $(OUTPUT)
+XDP_FEATURES_SRC := xdp_features.c network_helpers.c

I'm missing the point of these xxx_SRC variables, given you then go and list .h
files explicitly... Just have an inline list of all the dependencies, maybe?

pw-bot: cr

Good point, thanks.

The *_SRC variables were only grouping .c files, but since they are
single-use and the remaining dependencies still need to be listed
explicitly, they don’t improve readability much. I’ve inline the
dependencies directly in the rules in v2.

quoted

+$(OUTPUT)/xdp_features: $(XDP_FEATURES_SRC) xdp_features.h

network_helpers.h \

quoted

+                          test_progs.h bpf_util.h $(OUTPUT)/xdp_features.skel.h \
+                          $(BPFOBJ) | $(OUTPUT)
        $(call msg,BINARY,,$@)
        $(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@

--
2.43.0